After going missing shortly after the work's premiere in 1908, the score was undiscovered until 2004 when it was sold at auction. It is now hoped the complete manuscript will add to existing scholarship around the music; as well as being in good condition, the score itself sheds light on Rachmaninov's original intentions, with deletions, corrections and annotations by the composer himself.

"Apart from the corrected page-proofs now in Moscow, there are no other surviving manuscripts that give us any insight into the genesis and evolution of Rachmaninov's symphony," Sotheby's said. "No sketches, short-score draft, copyist's manuscripts or proofs seem to have survived: this seems to be the sole and most important source for the Second Symphony."

As well as important musical works, other items on sale today included leaves from the Gutenberg Bible, a copy of Aesop's Fables from 1501, and early editions of scholarly texts by Kant and Luther.